The United States declared war on the German Empire on April 6, 1917, nearly three years after World War I started. A ceasefire and Armistice was declared on November 11, 1918.Before entering the war, the U.S. had remained neutral, though it had been an important supplier to the United Kingdom, France, and the other powers of the Allies of World War I.

The 11th Airborne Division ("Arctic Angels") is a United States Army airborne formation, first activated on 25 February 1943, during World War II.Consisting of one parachute and two glider infantry regiments, with supporting troops, the division underwent rigorous training throughout 1943. It played a vital role in the successful Knollwood Maneuver, which was organized to …

Lengths of U.S. combat forces' participation in wars. War in the context of this list is broadly construed to be a direct armed conflict between organized U.S. military forces and organized forces of (a) belligerent(s). (Note: Ongoing wars are indicated in bold and with red bars.)

The history of the United States from 2008 to the present began with the collapse of the housing bubble, which led to the Great Recession.The resulting economic downturn and general discontent led Barack Obama to win the presidential election in 2008, becoming the country's first African-American president. Obama's domestic agenda notably included economic stimulus …

World War II was the deadliest military conflict in history.An estimated total of 70–85 million people perished, or about 3% of the 2.3 billion (est.) people on Earth in 1940. Deaths directly caused by the war (including military and civilian fatalities) are estimated at 50–56 million, with an additional estimated 19–28 million deaths from war-related disease and famine.

The 1920 United States presidential election was the 34th quadrennial presidential election, held on Tuesday, November 2, 1920.In the first election held after the end of World War I and the first election after the ratification of the Nineteenth Amendment, Republican Senator Warren G. Harding of Ohio defeated Democratic Governor James M. Cox of Ohio. ...